Project description:Sperm carries information to the presumptive embryo upon fertilization in terms of epigenetic codes and transcripts along with the haploid genome. The epigenetic code includes DNA methylation and histone modifications. During spermatogenesis, the DNA of sperm undergoes overall methylation changes and this could have some role to play in fertilizing ability of the sperm. Many of the studies have shown that the altered methylation can cause sub fertility. In the present study we report the development of first comprehensive 4X180K buffalo (Bubalus bubalis) CpG island/promoter microarray for studying the global DNA methylation profile of buffalo sperm. The array has been developed by employing microarray based comparative genomic hybridization (aCGH) technique with bovine and buffalo DNA using bovine genome sequence as reference. The array represents 157084 features assembled from CDS, Promotor and CpG regions covering 2,967 unique genes. We also report the comparison of genome wide methylation differences in buffalo sperm from high fertile and sub fertile bulls which indicated profound discrepancies in their methylation status. A total of 96 individual genes along with another 55 genes covered under CpG islands were found differentially methylated and and were associated with different cellular functions and biological processes affecting germ cell development, spermatogenesis, capacitation and embryonic development.
Project description:Sperm carries information to the presumptive embryo upon fertilization in terms of epigenetic codes and transcripts along with the haploid genome. The epigenetic code includes DNA methylation and Histone modifications. During spermatogenesis the chromatin of sperm undergoes wide level of modifications and histone proteins are replaced by Protamine proteins. But some modified Histone forms still remain and they carry epigenetic codes essential for fertility and embryo development. Through this work we are trying to see the difference between H3K4me2 and H3K27me3 kind of histone modifications in spermatozoa of high and low fertility buffalo bulls.
Project description:Abstract The water buffalo (Bubalus bubalis) is an indispensable part of the Indian dairy sector and in several instances, the farmers incur economic losses due to failed pregnancy after artificial insemination (AI). One of the key factors for the failure of conception is the use of semen from the bulls of low fertilizing potential and hence, it becomes important to predict the fertility status before performing AI. In this study, the global proteomic profile of high fertile (HF) and low fertile (LF) buffalo bull spermatozoa was established using a high-throughput LC-MS/MS technique. A total of 1385 proteins (≥ 1 high-quality PSM/s, ≥ 1 unique peptides, P < 0.05, FDR < 0.01) were identified out of which, 1002 were common between both the HF and LF groups while 288 and 95 proteins were unique to HF and LF groups respectively. We observed 211 and 342 significantly upregulated (log Fc ≥2) and downregulated in HF (log Fc ≤0.5) spermatozoa (p <0.05). Gene ontology analysis revealed that the fertility associated upregulated proteins were involved in spermatogenesis, sperm motility, acrosome integrity, zona pellucida binding and other associated sperm functions. Besides this, the downregulated proteins were involved in glycolysis, fatty acid degradation and inflammation. Furthermore, fertility related differentially abundant proteins (DAPs) on sperm viz., AKAP3, Sp17 and DLD were validated through Western blotting and immunocytochemistry which was in coherence with the LC-MS/MS data. The DAPs identified in this study may be used as potential protein candidates for predicting fertility in buffaloes. Our findings provide an opportunity in mitigating the economic losses that farmers incur due to male infertility.
Project description:The aim of this study was to examine changes in the mRNA transcriptional profile of spermatozoa in Holstein-Friesian bulls. Spermatozoa from bulls divergent for feritlity status were used for this study with 10 High fertility bulls and 10 Low fertility bulls. RNA was extracted and subsequently subjected to miRNAseq analysis. 6 miRNA were identified as differentially expressed in the spermatozoa between bulls of high and low feritlity status.
Project description:The aim of this study was to examine changes in the miRNA transcriptional profile of spermatozoa in Holstein-Friesian bulls. Spermatozoa from bulls divergent for feritlity status were used for this study with 10 High fertility bulls and 10 Low fertility bulls. RNA was extracted and subsequently subjected to miRNAseq analysis. 13 miRNA were identified as differentially expressed in the spermatozoa between bulls of high and low feritlity status.
Project description:Gonadotropin surge acts on the preovulatory follicle of the ovary to induce luteinization of follicular cells, oocyte meiotic maturation, cumulus expansion and follicular rupture leading to ovulation. These processes are brought about by spatial and temporal changes in transcriptional regulation of genes in the follicular cells in response to the gonadotropin surge. Analysis of gene expression changes in the periovulatory follicular cells will help in delineating the signal transduction pathways involved in the above mentioned processes. In monoovulatory species like bovines, the time interval of 24-28 hours between gonadotropin surge and ovulation provides distinct advantage for studying the temporal changes in the gene expression pattern. Thus, in the present study, we attempt to identify the temporal changes in the global gene expression profile in the periovulatory follicle of buffalo cows in response to gonadotropin surge and the results suggest the involvement of Insulin-like Growth Factor 1 and cytokine signaling pathways in the periovulatory events. Experiment Overall Design: To study the periovulatory gene expression changes in buffalo cows, an induced-ovulation model system involving sequential treatment with PGF2alpha and GnRH was standardized. The follicular wave containing at least one large follicle of ~7mm size was determined by ultrasonography on day 7 of the estrous cycle before administering exogenous PGF2alpha to induce luteolysis and follicular growth. Exogenous GnRH (100µg i.m) was administered 36h post PGF2alpha to induce LH surge. The time course of increase in LH levels post GnRH injection was monitored. Since peak LH levels are attained 2 h post GnRH administration, the time intervals of 3 h post GnRH (corresponding to1 h post LH surge) and 24 h post GnRH (corresponding to 22 h post LH surge) were chosen to identify the gene expression profile associated with immediate early and delayed changes in periovulatory follicle respectively. Thus ovaries were collected before, 1 h and 22 h post LH surge and follicle wall and granulosa cells were isolated from the ovaries and snap frozen for the purpose of RNA isolation.